The invention concerns a device for guiding and affixing an endoscope and a matching adapter. This device is technically applicable wherever inspections are required of sites of difficult access such as cavities or machine components by visual examination using an optical means, for instance rigid or flexible endoscopes. This applies in particular to monitoring drive systems of all kinds, especially aircraft power plants, and as regards latter, their blades and combustion chambers.
When inspecting components inside machines, the observer must be able to recognize these components in problem-free manner in order to be able to spot the last damage. This is possible only using a device to guide and affix an endoscope anywhere. The endoscope no longer must be held by the observer.
In order to explain the state of the art, the industrial use of endoscopes will be illustrated with reference to aircraft power plants. At those places of the power plant where provision is made for inspection of the inside, plugs are located in the powerplant casing and are screwed loose; there are also blank flanges of pipe connectors that will be removed.
A rigid or flexible endoscope is inserted through the opening so created, which may assume various diameters, and thereby checking will start. During the entire examination the observer is holding the endoscope and, depending on where he stands or his physical constitution, his body may sway. Ascertained damages must be located again and comparative photographs must be made. The observations so made must be corroborated by other expert person(s).
Optimal observation is impossible because the endoscope is held freely while the body may sway. It must be made possible to the observer to assure problem-free recognition of the components over the entire distance between the close and far recognition points without himself having to hold the endoscope. Only in this manner shall it be possible to discover the tiniest damages and relocate them again. Work based on the present state of the art is highly time-consuming and hence expensive, moreover endoscopes are frequently damaged and as a result cause longer inspection times and also substantial costs for repairs or new acquisitions of endoscopes. Endoscopes incur damage by being tilted in the inspection aperture and by being moved over its sharp-edged threads. The optics is often damaged by hitting the edge of this inspection aperture.
Where second or third persons are involved, it is time-consuming and difficult to relocate previously ascertained damages because other angles of view and hence observed scenes follow from the free holding of the endoscope. Where comparison photographs must be take, the cost in time increases because the endoscope is not fixed in place and blurred images arise from motion. In that case the endoscope most of the time will be tilted to prevent it from moving.
Known devices for guiding an endoscope are for flexible ones and no longer are used in the present generation of powerplants.
U.S. Pat. No. 4,298,312 and also British patent 20 33 973A describe a device with a tubular segment of present curvature through which an endoscope may be moved but cannot be affixed.
These known devices are applicable only to special cases.
The same condition holds for the German patent document 37 07 368 A1 with the assembly plate described therein with the holding elements for a guiding tube.
That invention entails another drawback, namely that depending on the application, the stop means and joints and the many connections by clamps require substantial set-up time and following frequent use, they will convert the individually applied forces into device damage.
The object of the British patent 20 33 973 A suffers from the further drawback that the guide tube is axially displaced by a screw and therefore there is no possibility of rotating the tube and hence the endoscope; moreover the affixing of the tube by a further screw acting on the outer tube ipso facto damages same and thereby axial displacement is hampered where not impossible.
In the U.S. patent mentioned above, the flexible endoscope is not held in the tube and therefore must be corrected when the tube is axially displaced.